AAMC Bio

Question 1

What is the function of a chaperone protein?

Answer 1

A protein that facilitates proper folding and inhibits the formation of nonfictional protein aggregates such as heat shocked proteins are an example of chaperone proteins.

Question 2

If deletions in a microsatellite on an intron cause an Exon to be omitted from the final mRNA what does it suggest about the microsatellite?

Answer 2

It would suggest that the microsatellite contains sequences that influence splicing such as an splice acceptor site.

Question 3

What are the letters single letter abbreviations of the charged amino acids?

Answer 3

From acidic to no basic D, E, H, C, Y, K, R

Question 4

What are the amino acids that are aromatic? What are their single letter abbreviations Which one are non-polar?

Answer 4

Tyrosine, tryptophan, Phenylalanine, histadine Y, W, F, H

Question 5

Nicotinamide nucleotides are neither oxidized nor reduced during which step of cellular respiration?

Answer 5

NAD+ is no reduced nor NADH is oxidized during the step of CHEMIOSMOSIS step of cellular respiration.

Question 6

During the initiation of muscle contraction?

Answer 6

Free Ca2+ in the cytosol binds to troponin, which pulls tropomyosin away from actin’s myosin-binding site. This allows myosin to bind to actin.

Question 7

How are steroids defined as?

Answer 7

Steroids are fined by its fused 4-ring structure.

Question 8

A drink for the treatment of epilepsy would be most effective if it?

Answer 8

Increase the threshold required to generate an action potential. This would decrease the chance that individual neurons would fire, reducing the overall amount of excitation spreading from the epileptic focus to the rest of the cortex.

Question 9

In which region of the kidney is urine the most concentrated?

Answer 9

The glomerular filtrate is most concentrated in the medullary portion of the collecting duct.

Question 10

What properties are activity and free energy?

Answer 10

Free energy is a thermodynamic property. Activity is a kinetic property.

Question 11

What is the function of the Na+K+ ATPase during a neuronal action potential?

Answer 11

Na+K+ ATPase functions to restore the resting membrane potential by moving the ions against their concentration gradients.

Question 12

In which direction does the Na+K+ ATPase transport ions across the cell membrane upon ATP hydrolysis?

Answer 12

Na+K+ ATPase transport 3 sodium ions out of the cell and 2 potassium ions into the cell with each ATP hydrolyzed.

Question 13

Where do transcription factors bind to?

Answer 13

They bind to the DNA.

Question 14

In order for a molecule to diffuse directly through the membrane, it must have? Explain

Answer 14

It should show sufficient planarity and hydrophobicity to pass through the membrane by simple diffusion. Planarity refers to the number of sp2 hybridization, trigonal planar. Benzene rings show planarity.

Question 15

Proteins such as PKC, which are kinases perform what type of action.

Answer 15

Phosphorylation, addition of phosphate groups.

Question 16

Which mechanics describes how P-gp facilitate drug resistance? ABC is transporter protein according to the passage.

Answer 16

P-gp as an ABC transporter protein, uses ATP to actively transport anti tumor drugs out of the cell.

Question 17

If ATPase activity is increased what is expected to happen?

Answer 17

ATPase is responsible for ATP hydrolysis, which produces ADP and inorganic phosphate. So the production of ADP+Pi would be INCREASED.

Question 18

What is the most likely location for a protein within the plasma membrane? If according to the passage located in the cholesterol-rich domains?

Answer 18

If the protein is found in the cholesterol rich domains, it would indicate that the protein is located within a lipid raft.

Question 19

MBCD is composed of which type of molecule? According to the passage it is a cyclic oligosaccharide.

Answer 19

A cyclic oligosaccharide means it is composed of carbohydrates

Question 20

Colchine is a drug that prevents the formation of microtubules. Which mototic process will be disturbed after exposure to this drug?

Answer 20

Microtubules function in chromosomal movements in cell division. So, the movement of chromosomes toward opposite poles of the cell during anaphase will be disturbed.

Question 21

The initial filtration step in the glomerulus of the mammalian kidney occurs primarily because?

Answer 21

Passive flow due to pressure difference. The initial filtration in the glomerulus occurs as blood pressure forces the liquid from the glomerulus into the lumen of the Bowman’s capsule.

Question 22

If according to the graph it takes half an hour to fall by one half. After 5 half lives how much urea will be there? If the initial concentration of was 200 ng/mL

Answer 22

.5•5 in two hours and a half there will be 200/2^5= 6.5ng/mL

Question 23

If you want to determine how long will a specimen take to disappear using half life what process do you use? Note: they tell you how many half lives it takes and graph of decay.

Answer 23

Determine how long it takes the compound to fall by one half and multiply that time by the number of lives given.

Question 24

What are some of the action enzymes can do and CANNOT do.

Answer 24

Enzymes can colocalize substrates, alter local pH, and alter the substrates shape. Enzymes cannot alter a substrate primary structure.

Question 25

What is a fundamental reason an amino acid would be found in cells, but not be incorporated into proteins?

Answer 25

That there is no codon for it in the standard genetic code. An amino acid without a corresponding codon in the genetic code cannot take part in the process of protein translation.

Question 26

The ending -ase such as in ornithine decarboxylase refers to?

Answer 26

An enzyme a catalyst

Question 27

What does it mean when an enzyme is highly specific?

Answer 27

It means that the enzyme is highly specific on the reactions that they catalyze and in their choice of substrate, and therefore catalyze only a single chemical reaction or a occasionally a set of closely related reactions.

Question 28

Acetyl CoA is the main input of what process?

Answer 28

Acetyl coenzyme A is the main input in the citric acid cycle.

Question 29

Glycolysis occurs .. whereas the Karen’s cycle occurs…

Answer 29

Glycolysis occurs in the cytoplasm where as the Karen’s cycle occurs in the inner space of the mitochondria

Question 30

Protein levels relate most directly to?

Answer 30

mRNA levels.

Question 31

What is an inducible enzyme?

Answer 31

An enzyme which production requires the stimulation by another molecule. Such as a detoxifier when alcohol is consumed. Getting rid of the alcohol or barbiturate

Question 32

In which phase of the cell cycle would a cell not be dividing, and instead performing regular metabolic activities? Which activities are those?

Answer 32

The interphase is the phase where the cell will not be actively dividing and instead it is the phase where the cell obtains nutrients, grows, reads its DNA and conduct “normal” cell functions.

Question 33

What happens to the nucleous of erythrocytes.

Answer 33

Erythrocytes loose their nucleous during maturation. Therefore, circulating erythrocytes do not contain DNA, cannot synthesize any RNA, cannot divide, and have limited repair capabilities.

Question 34

The fact that viruses can only replicate inside a host makes them?

Answer 34

Obligate intracellular parasites.

Question 35

What component is not important in bacterial cells given that their chromosomes are circular?

Answer 35

Telomeres are a repetitive non-coding nucleotide sequence that are present in eukaryote.

Question 36

How are nucleotides linked to one another?

Answer 36

Nucleotides are linked to one another by phosphodiester bonds between the sugar base of one nucleotide and the phosphate group of the adjacent nucleotide in a way that the 5’ end bears the phosphate and the 3’ end a hydroxyl group. Effectively making a bond between the sugar of one nucleotide and the phosphate of the adjacent one.

Question 37

Aldosterone deficiency associated with Addison’s disease will not cause a decrease of which ions? According to the passage aldosterone causes the retention of Na+ and the excretion of K+

Answer 37

Given that aldosterone causes the excretion of potassium, low levels of aldosterone will no cause the potassium ions concentration to go down.

Question 38

If a patient with Addison is given too high a concentration of glucocorticoids it would result in? According to the passage, excess glucocorticoids, between other things, cause the mobilization of amino acids from muscle tissue.

Answer 38

If a patient is given to high a dose of glucocorticoids the amino acids from muscle tissues will be mobilized causing muscle breakdown and weakness.